Table 1.
Descriptive characteristics of participants who had received the COVID-19 vaccine and reported changes in their menstrual cycles (n = 545)
| n (%) | |
|---|---|
| Reported changes in the menstrual cycle after COVID-19 vaccination | 135 (24.8) |
| When they first noticed changes | |
| After 1st dose | 25 (18.5) |
| After 2nd dose | 76 (56.3) |
| After 3rd dose | 19 (14.1) |
| Unsure | 15 (11.1) |
| Menstrual changes resolveda | |
| Yes, I am no longer experiencing changes | 24 (17.8) |
| No, I am still experiencing changes | 71 (52.6) |
| I don’t know | 28 (20.7) |
| Time until changes resolved (mo)b | |
| 1 | 4 (16.7) |
| 2 | 10 (41.7) |
| 3 | 3 (12.5) |
| 4 | 3 (12.5) |
| 5 | 2 (8.3) |
| 6 | 2 (8.3) |
| Specific changes in the menstrual cycle–at the first reported change in the cycle | |
| One or more missed menstrual periods | 16 (11.9) |
| Infrequent menstruation (i.e., menstrual periods occurring at intervals >35 d) | 14 (10.3) |
| Irregular menstruation (i.e., the number of days your menstrual period lasts or the time between each varies significantly) | 58 (43.0) |
| Abnormal bleeding or spotting between normal menstrual periods | 32 (23.7) |
| Abnormally heavy or prolonged bleeding (i.e., bleeding for longer than a wk, needing to use double the sanitary protection to control your menstrual flow) | 42 (31.1) |
| Abnormally light bleeding | 22 (16.3) |
| Increase in menstrual pain or cramps | 41 (30.4) |
| Increase in premenstrual symptoms (i.e., greater than usual mood swings, feelings of anxiety/depression, tiredness, trouble sleeping, bloating/stomach pain, breast tenderness, changes in appetite or sex drive) | 46 (34.1) |
| Survey where participant reported their first vaccination | |
| Baseline | 135 (100) |
| 3 mo | 0 (0) |
| 6 mo | 0 (0) |
| Percent of participants that reported changes in their menstrual cycle by surveyc | |
| Baseline | 101 (74.8) |
| 3 mo | 22 (16.3) |
| 6 mo | 12 (8.9) |
| Mean (SD) Median [min-max] |
|
| Days from the first vaccine dose to the completion of the first survey where they reported a change in their menstrual cycle | 137 (79) 118.5 [29-380] |
| Days from the second vaccine dose to the completion of the first survey where they reported a change | 112 (79) 91 [6-359] |
| Days from the first vaccine dose to completion of the first survey where they reported resolution to menstrual changes | 166.8 (69.5) 152.5 [61-352] |
| Days from the second vaccine dose to completion of the first survey where they reported resolution to menstrual changes | 141.9 (69.8) 125.5 [39-331] |
a
Missing data for changes resolved (n = 12, 8.9%) at the last reported survey.
b
Among those who reported changes had resolved (n = 24); based on the write-in question: “Approximately how many months after vaccination did these changes resolve?”
c
545 participants completed the baseline questionnaire, 417 completed the 3-month questionnaire, 391 completed the 6-month questionnaire.